Control for internal-combustion engines or the like



Sept. 19, 1944, F. w. TRUESDELL CONTROL FOR INTERNAL-COMBUSTION ENGINESOR THE LIKE Filed Nov. 7, 1942 2 Sheets-Sheet l Inventor: Francis W.Truesdetl,

His Attorney.

Sept. 19, 1944.

F. W. TRUESDELL CONTROL FOR INTERNAL-COMBUSTION ENGINES OR THE LIKE 2Sheets-Sheet 2 Filed NOV. 7, 1942 Inventor: Francis W. Truesdell,

H "His Attorney.

Patented "Sept. 19, 1944 CONTROL FOR INTERNAL-COMBUSTION ENGINES OR THELIKE Francis W. 'Iruesdell, Marblehead, Mass, assignor to GeneralElectric Company, a corporation of New York Application November 7,1942, Serial No. 464,882

21 Claims.

The present invention relates to control arrangements for internalcombustion engines or the like. It is especially useful in connectionwith aircraft internal combustion engines and it is this application ofmy invention which I have elected to illustrate and describe. It is tobe understood, however, that this is only by way of example and that theinvention may be used wherever found applicable.

An object of my invention is to provide an improved construction andarrangement for adlustin automatically the throttle valve or otherregulating means ofan engine, such as an internal combustion engine, inresponse to changes in an operating condition of the invention, such as,for example, changes in engine intake manifold pressure, to maintainsuch operating condition at a desired value.

For a consideration of what I believe to be novel and my invention,attention is directed to the following specification and the claimsappended thereto.

In the drawings, Fig. 1 is a diagrammatic view of an embodiment of myinvention, and Figs. 2 and 3 are diagrammatic views of modifications.

Referring to the drawings, l indicates an internal combustion engine,which may be an aircraft engine driving a propeller 2. At 3 is indicated a gear driven supercharger for the engine having its inletconnected to an air supply conduit 4 and its outlet connected to theengine intake conduit or manifold '5. In conduit 4 is a throttle valve 6which controls the flow of air and fuel to the intake manifold. Acarburetor is indicated at I and a fuel supply pipe at 8. -Air to thecarburetor may b obtained from any suitable source, for example, a ramfacing into the slip stream of the aircraft with which conduit 4 isconnected. On the spindle of throttle valve 6 is fixed an arm 9 throughwhich the throttle valve is adjusted.

According to one embodiment of my invention, I provide a control systemwhereby throttle valve 6 may be manually controlled or whereby it may beautomatically controlled by means responsive to an operating conditionof the engine. Preferably, I control the throttle valve by the pressurein manifold to maintain constant the manifold pressure and it is thisapplication of my invention which I have elected to specificallyillustrate and describe.

Arm 9 is connected by a link ill to an arm H fixed on a rotatable shaftI2 whereby as shaft 12 is oscillated in one direction and the other, thethrottle valve 8 is opened and closed. Shaft I2 is driven by a reversingmotor i3, the shaft l4 of which is connected to shaft l2 through asuitable reduction gearing l5 and a clutch l6. Clutch I6 is actuated bya lever i'l to one end of which is connected a spring which biases theclutch to open position. It is adapted to be closed by a solenoid IS,the plunger of which is connected to lever i'I. When the winding ofsolenoid I9 is energized, clutch I3 is closed against the action ofspring l3. When the solenoid I9 is deenergized, spring It opens thclutch. Lever i1 is shown as being fulcrumed at 2| and it is provided atits one end with a fork 22 having inwardly directed pins which engage ina groove in the clutch collar. The clutch member with which the pins onfork 22 engage is keyed to its shaft but is adapted to slide axiallythereon to permit the engagement and disengagement of the clutch. Fixedon motor shaft I4 is a brake disk 23 adapted to be engaged by a frictionbrake member 24 on one end of a lever 25. Lever 25 is pivoted at 26 andis biased to a position wherein friction brake member 24 engages disk 23by a spring 21. The brake member is adapted to be released by a solenoid28, the plunger of which is connected to the other end of lever 25,

' Pivotally connected to arm II is a link 30 having in one edge a notch3| adapted to fit over a head 32 on the end of a sliding link 33 whichslides across a fixed block 34. Link 33 is pivotally connected to onearm 35 of a bell crank lever pivoted at 36. Also connected to lever arm35 is a rod 31 which at its other end is pivotally connected to thelower end of manually operable control lever 38 pivoted at 39. Whennotch 3| engages head 32, throttle valve 6 may be moved by means of handlever 38, a movement toward the left acting to move valve 6 towardclosed position and a movement toward the right acting to move valve 6toward open position. Link 30 is adapted to be moved to disconnect itfrom link 33 by a solenoid 40, the plunger of which is provided with apin which engages in an elongated slot in link 30. Link 30 is biased toa position wherein notch 3| engages head 32 by its weight. With thisarrangement, when solenoid 40 is energized, hand lever 38 isdisconnectedfrom the throttle valve. it is connected to the throttle valve.

The other arm 4| oi the bell crank lever is connected through a tensionspring 42 to the movable contact arm 43 of an absolute pressureresponsive device 44. The absolute pressure responsive device is showndiagrammatically as comprising an evacuated bellows 45 carried on Whensolenoid 40 is deenergized,

matically in the drawings.

a fixed support 46 and a second opposed bellows 41 carried on a fixedsupport 48, the free ends of the two bellows being connected by a pin49, which pin in turn is connected to contact arm 43. The interior ofbellows 41 is connected by a pipe line 58 to intake manifold at a pointbeyond gear driven supercharger 3. The pressure responsive device'44responds, therefore, to the absolute pressure in the intake manifold. An

increase in pressure acts in a. direction to move contact .arm 43* downand a, decrease in pressure permits spring 42 to move it upward. Thetension spring 42 may be set for different manifold pressures by handlever 38.

Motor I3 has two windings, a winding 5| which when energized effectsturning movement of shaft l2 in a direction to open valve 6 to increasethe pressure in manifold l5, and 'a winding 52 which operates the motorto turn shaft I2 in a direction to move valve 6 toward closed positionto decrease the manifold pressure. The common terminal of motor windings5i and 52 is connected by a conductor 53 through a source of electricalenergy 54 to ground at 58', such circuit includin the winding ofsolenoid 28 and a main control switch '55 located in the vicinity ofhand lever 38 so that it may be opened and closedby the operator. Theother terminal of motor'winding 5i is connected by conductor 58 to oneterminal of a limit switch 5?, the other terminal of which is connectedby a conductor 58 to one contact 59 ofa pair of relay contacts, theother contact 59 of the pair being connected by a conductor 88 to aswitch contact 54. Similarly the other terminal of motor winding 52 isconnected by a conductor 82 to one terminal of a limit switch 83, theother terminal of which is connected by a conductor 83 to one contact esof a pair of relay contacts, the other contact 85 of the pair beingconnected by a conductor 58 to a switch contact 5?. Limit switches illand 53 are adapted to be opened by an arm t8 fixed on shaft 92 andturning with it. Connected with shaft :12 is a spring structure 8?;which acts to bias shaft 62 to a predetermined position, for

example, to a position in which valve 5 is open or to a position inwhich it is partially open. The limit switches are biased to closedpositions by suitable springs, as is indicated diagram- Contaots 59, 59-and 55, 65* are contacts of relays 78 and H, respectively, the cores l2and 33 of which are grounded, as indicated at 18. When energized, relayit engages contacts 59 and 59 and relay M engages contacts 85 and 65 Thewinding of relay i8 is on one side connected by a conductor 75 tocontrol contact 18 and on the other side by a conductor ii to a pair ofspaced contacts i8 and '39. Similarly, one side of the winding of relayH is connected by a conductor 88 to control contact 8! and on the otherside by a conductor 82 to a pair of spaced contacts 83 and 84. Oppositecontacts BI and 51 are contacts 85 and 88 which are connected byconductors 8V and 53 to source 54. Contacts 6|, F9 and 85, '18 areadapted to be bridged by connector 88, the connector when in oneposition bridging contacts 6i and 19 and when in the other positionbridging contacts 85 and 18. Similarly. contacts 61, 84 and 88, 83 areadapted to be bridged by a connector 89, the connector when in oneposition bridging contacts 61 and 84 and when in the other positionbridging contacts 86 and 83. Connector 88 is biased into enga ement withcontacts 6| and 19 by a spring 99 and connector adapted to be moved fromthe one set of contacts into engagement with the other set of contactsby an arm 92 which engages pins 93, 94 carried by connectors 88 and 89,respectively. The arm is provided with a head 85 which engages shaft l2and is frictionally clamped thereto by a, screw 96. The screw 96 isadjusted so that frictional contact between the head and shaft I2 issuch that when shaft l2 turns, arm 92 moves with the shaft until arm 92engages one or the other of the pins 93, 94 and moves connector 88 or 89into engagement with its other set of contacts after which shaft I2 willturn in head 95, arm 92 remaining stationary.

The windings of solenoids l9 and 48 are connected in a circuit in serieswith each other and with source 54 by conductors 91. At [22 is apressure gauge which is connected to manifold 5 for indicating thepressure in the manifold. Connected across contacts 65, 65 is aresistance 98 and similarly connected across contacts 58, 59 is aresistance 99.

The operation is as follows: Assume that the engine is operating withmanual control, the parts being in the positions shown in Fig. 1. Bymoving lever arm 38 the operator can control the engine manually in theusual manner, adjusting the throttle valve 6 for the desired intakemanifold pressure, using gauge I22 to direct him. Such movement of leverarm 38 adjusts also the tension of spring 42 to set the pressureregulator for a corresponding pressure but this has no immediate effect.7

Now if it is desired to utilize the automatic control, switch 55 isclosed. When switch 55 is closed, a circuit is closed on the windings ofsolenoids i9 and 58 by conductors 53 and 9'? whereupon solenoid l9eiiects engagement of clutch it and solenoid 89 lifts link 39 todisengage notch 39 from head 32, thus disconnecting the manual controlIf at this time the pressure in manifold 5 is that for which pressureregulator 5 3 is set, then contact arm 63 will stand midway betweencontacts and 8 l, as shown in the drawings. If now the pressure in theintake manifold increases, contact arm 43 will move into engagement withcontact 8!. This closes a circuit on the winding of relay H as follows:From ground 55 switch 55, conductor 53, winding of solenoid 28, motorwinding 52, conductor 52, limit switch 63, conductor 85, resistance 98,conductor 58, connector 89, conductor 82, winding of solenoid H,conductor 88, contact 8! and contact arm 43 to ground, causing the relayto pick up and engage contacts and 65 The circuit just traced includesmotor winding 52 and the winding of solenoid 28. However, these windingsare of relatively low resistance and few turns as compared to thewinding of relay H which is of relatively high resistance and many turnsso that neither the motor nor the brake is afiected when this solenoidwinding circuit is closed. Relay contact 65 controls an operatingcircuit for motor l3 and relay contact 65 controls a short-circuitingcircuit for short-circuiting the assases gages contact a prior to itsengagement with contact 85'. In th drawings, contact 88 is shown asbeing so adjusted that the bridging member of relay ll engages it priorto the time it en- 8 88s contact 85 (the bridging member may havesuflicient flexibility or be otherwise arranged to permit of itsengaging the contacts successively) but this is only by way of example.

When the bridging member of relay H engages contact 85, a circuit isclosed in shunt to the winding of relay II as follows: source 84,conductor 83, solenoid winding 28, motor field winding I2, conductor 82,limit switch 88, conductor 84, resistance 98, and contact 85" to ground14. As a result, the winding of relay II is deenergized and th relay ifree to drop to open position.

Here again, the circuit just traced includes the winding of solenoid 28and the field of motor 18. However, resistance 88 is of a value suchthat the solenoid 28 and the motor I8 will not be operated.

When the relay bridging member engages contact 85, it closes a motor andbrake circuit as a value of the order of one-half R. P. M. Theresistance 88, in addition to preventing iull lt ge being applied tomotor 18 to prevent operation of it when the short-circuiting circuitfor the winding 01' relay 1i isclosed prior to the closing of the motorcircuit, performs also the iunction'oi' tending to prevent arcing at thecontacts.

After the motor has turned shaft I2 a predetermined amount, arm 82engages pin 84 to move follows: source 54, conductor 58, winding ofbrake solenoid 28, motor windin 52, conductor 82, limit switch 83,conductor 84, and contact 88 to ground I4; Thusthe full voltage ofsource 84 is applied to the solenoid and motor winding efiecting releaseof the brake and starting the motor to operate in a direction to movethrottle valve 8 toward closed position to effect a decrease in themanifold pressure.

With the above-described arrangement, it will be seen that when thecircuit on the winding of relay II is closed and the relay operates, twothings occur: the motor circuit is closed by the one relay contact and ashunt circuit is closed around the relay winding by the other relaycontact. As a result, the relay immediately returns to open position,opening the motor circuit. As soon as relay 1| moves to open position,the shunt around the winding of the relay is opened and the-relay isagain energized to again connect the motor in circuit and the cycle justdescribed is repeated. Thus the motor circuit is successively closed forshort intervals to successively start and stop the motor, the throttlevalve being moved by successive small movements toward open position,

With contacts 85 andii adjusted as shown, the engagement of the bridgingmember of solenoid II with contact 85 is effected due to themertia ofthe moving parts, the winding of the solenoid being actually deenergizedprior to the time the bridging member engages contact 85. Contacts 85and Eli are 50 adjusted relatively to each other that the motor circuiti closed for the desired length of time. Preferably, the arrangement issuch that the relay operates at relatively high speed. For example, itmay be closed for an interval of the order of ,60 to 5 second. Thearrangement may be such that brake solenoid 28 does not have time tore-engage between relay operations. Thus the brake is held released andthe motor circuit is closed for successive short interval to effectsuccessive small movements of valve 6.

The relay functions in substance to form a speed reducing means formotor i3 whereby it may be operated at a fraction of its normal speed.By way of example, in the case of a motor having normal speed with fullvoltage continuously applied of the order of 4 R. P. M., I may, ineffect, by applying to it successive short current imconnector 88 fromengagement with contacts 81 and 84 and into engagement with contacts 88and 88. This then closes a circuit directly on the winding of solenoidII as tollows:source 84, conductors 88, conductor 81, contacts 88, 88,conductor 82, winding of solenoid H, conductor 80, contact 8| andcontact arm 48 to ground, thus maintaining the solenoid windingcontinuously energized. The motor circuit is now held permanently closedby solenoid H and the motor will operate continuously at its full speeduntil such time as valve 8 has been opened an amount to decrease thepressure in manifold 5 to a value such that pressure responsive device44 moves contact 48 out of engagement with contact 8|. When this occurs,the various parts are restored to their normal positions.

If a decrease in manifold pressure occurs, contact arm 48 is moved intoengagement with contact l8 whereupon an'operation similar to that justdescribed takes place through actuation of relay 18, motor winding 5|being energized toef- Iect operation of motor H in the oppositedirection to effect an opening movement of throttle valve 8 to increasethe pressure in intake manifold 5. The circuits for relay I8 and motorwinding 8! are similar to those already described for relay II and motorwinding 52 and will be clear from an inspection of the drawings.

At any time, the operator can set the pressure regulator 44 for a higheror lower intake manifold pressure by moving hand lever 38 in a directionto increase or decrease the tension of spring 42. When the tension ofspring 42 is changed, immediately control arm 43 engages either contactIE or 8i to cause actuation of the throttle. y

By the foregoing arrangement, it will be seen that when regulator 44calls for an adjustment of the throttle valve, in the first instance thevalve is given a number of successive small movements, i. e., a numberof successive jogs toward open, or closed position, as the case may be.there has been but a small departure in the manifold pressure from thedesired value, then one or more small jogs may be suflicient to restorethe pressure and bring contact arm 43 to normal position where it is outof engagement with contacts 18 and 8|. On the other hand, if there hasbeen a substantial departure from the desired manifold pressure, thenwhen several successive jogs have failed to restore the pressure, themotor is connected permanently in circuit to effect continuous movementof the throttle valve until such time as the pressure is restored to thedesired value. Ordinarily, when this occurs, the pressure will movebeyond the desired value, bringing the pulses by the means described,reduce its speed to contact arm 43 out of engagement with the onecontact 16 or BI and into engagement with the other of these contacts,whereby the throttle valve will be given a. series of successive jogs inthe other direction. In other words, the pressure will overshoot so thata restoring in the opposite direction isrequired. This serves to efiecta more prompt return of the pressure to the desired value and givesstability in operation. When the motor circuit is opened at the end ofan interval of at a predetermined point. For example, spring structure69 may be arranged to move throttle valve 6 to idling position orsubstantially idling position. After the operator has opened switch 55,he moves hand lever 38 to a position wherein notch 3I drops over head32, if this has not already occurred when switch 55 was opened and shaftI2 turned by spring structure 69. The operator can now control thethrottle manually in the usual way.

As stated above, the successive increments of movement imparted to motorI 3 by the successive closings of its circuit by solenoids I0 and 'IIamounts in substance to'operating the motor through a reduction speedgearing. It has the advantage that by adjusting contacts 59, 59 or 65,65 relatively to each other, the amount of the speed reduction in eitherdirection can be adjusted accurately and in small steps.

In Fig. 2 is shown a modification wherein the operator first sets thethrottle valve manually for a desired intake manifold pressure afterwhich he may change to automatic pressure control to maintainautomatically the intake manifold pressure for which the throttle hasbeen set. If the operator desires to hold automatically a manifoldpressure other than that for which valve 6 was set manually, then hechanges from automatic to manual control, resets the throttle valve togive the desired intake manifold pressure and again shifts back toautomatic control. In Fig. 2, reference characters the same as thoseused in Fig. 1 with the exponent a added have been used to designatecorresponding parts.

At I00 is a shaft mounted in suitable bearings, not shown, and adaptedto turn about its longitudinal axis. Carried by shaft I00 is a block ofinsulation IOI on which are. mounted the two adjustable contacts I6 andBI and between which stands the contact arm 43 connected to an absolutepressure responsive device 0& here .shown in the form of a sealed casingI02 with which the pressure pipe 50*- leading from the engine manifoldis connected and in which is located an evacuated bellows I03, the stemI 00 of which extends out through an opening in casing I02 and isconnected to contact arm 43 The opening in casing I02 through which thestem passes is sealed by means of a flexible extensible sleeve I whichat one end is attached.

to casing I02 and at the other end to the stem I04. At I06 is a springwhich opposes movement of bellows I08. Fixed on shaft I00 is a disk I0'Iwhich is located between a pair of straps I00 which are pivoted to eachother and are adapted to be pulled together to clamp disk IM to holdshaft I00 stationary by means of the plunger of a solenoid I09. In thepresent instance, this is accomplished by a bell crank lever I I0pivoted at III and provided with pins II2 which stand on opposite sidesof spaced arms II 3 on straps I08. When solenoid I09 is energized, itsplunger moves downward, turning bell crank lever IIO to two projectionsII8 on lever 38 force arms H3 toward each other, and thus causing strapsI08 to clamp disk I131. The plunger of solenoid I09 is biased to aposition wherein straps I08 do not clamp disk I01 by a spring II l. Thewinding of solenoid I09 is in circuit S'I in series with the winding ofclutch solenoid i9, arm Ii is connected directly to hand lever 38 bylink 33 Associated with hand lever 38 is a switch means so arranged thatwhenever the hand lever is moved, the main circuit including conductor53 is opened. To this end, I have shown in the present instance an armII5 which is pivoted at IIS and has a knob H? by means of which it ismoved. It lies between and in spaced relation to On arm ii 5 is a pin II9 which stands between a pair of separable contacts E20 carried byspring arms i2I located in circuit 53 gagement with each other. Wheneverarm H5 is moved in either direction to efiect movement of hand lever38*", the contacts I20 are first separated by the initial movement ofarm II 5 after which the arm engages a projection IIB to move lever 38The lost motion between arm H5 and projections I I8 is suflicient toinsure separation of contacts I20 prior to any movement of lever Whenmain switch 55 in circuit 53 is open, the throttle valve is under directcontrol of hand lever 38 clutch IIS being open. The operator byadjusting lever 38 may adjust the throttle for the desired intakemanifold pressure, the pressure being shown on the manifold pressureindicator. The intake manifold pressure is applied to absolute pressuregauge I 03 through pipe 50 causing bellows I03 to assume a positioncorresponding to the pressure. As bellows I03 moves, the contact arm d3engages either contact I6 or contact 8!, effecting turning movement ofshaft I00 and bringing contacts "5 and M to a predetermined positioncorresponding to the intake manifold pressure. Shaft I00 can turnreadily at this time since solenoid I09 is deenergized so that clampsI08 do not clamp disk I01.

If now the operator desires to operate with automatic control, he closesthe switch 55 This effects energization of solenoids I 9 and I09.Energization of solenoid 19 closes clutch I6 and energization ofsolenoid I09 causes straps I08 to clamp disk I07, thus clamping contactsI6 and Bl in the position to which they have been moved by arm 33*, thisbeing a position which corresponds to the manifold intake pressure. Nowas the intake manifold pressure departs from the desired value, contact43 is moved into engagement with either contact I6 or contact 8Iefiecting adjustment of the throttle valve through operation of motor I3in the manner already described in connection with the operation ofFig. 1. When switch 55 is closed, if contact arm 03 is in engagementwith either contacts I6 or contacts 8", there will be an initialsmallthe intake manifold pressure for which contacts. I6 and 8I arepositioned will be automatically maintained. If now the operator desiresto increase or decrease the intake manifold pressure, he has merely tograsp knob I I! to adjust Normally contacts I20 are in en-' sireddirection. Initial movement of lever II! lever 18 to move the throttlevalve in the deefie'cts separation of contacts I20, thus opening circuit53 and deenergizing solenoids l9 and M9. This serves to open clutch l6and release shaft I011. The operator can now move lever 38 through theintermediary of lever Hi to change the position of the throttle valve soas to bring the intake manifold pressure to the desired value. At thissame time, contacts 18 and 8| will be adjusted in the manner alreadydescribed to a position corresponding to the new intake manifoldpressure. After the throttle has been adjusted for the new intakemanifold pressure, the operator releases lever'l l whereupon itimmediately returns to its central position between projections' H8,permitting contacts I20 to again close, thus closing the main circuitthrough conductor' 53 and again energizing solenoids l9 and I09. Themechanism will now operate automatically to maintain the new intakemanifold pressure.

With the above described arrangement, it will be seen that the operatormanually adjusts the throttle valve for the intake manifold pressure atwhich he desires to run the engine, after What I claim as new and desireto secure by Letters Patent of the United States is: l. The combinationwith an internal combustion engine having an intake conduit and athrottle valve for controlling flow oi combustible mixture to saidintake conduit, of manual means for positioning said valve, automaticmeans responsive to engine intake pressure for positioning said valve,means for transferring from manual to automatic control at will, andmeans responsive to movement of said manual means for adjusting thesetting of said automatic means.

2. The combination with aninternal combustion engine having an intakeconduit and a throttle valve for controlling flow of combustible mixture to said intake conduit, of manually operable lever: means forpositioning said valve, automatic means responsive to engine intakepressure for positioning said valve, means for disconnecting which themechanism automatically maintains such pressure. I i

In Fig. 3 is shown another modification of my invention wherein thesolenoid 40 of Fig. 1 or 40 of Fig. 2 is omitted, the link 33corresponding to link 33 of Fig. 1 and 33 of Fig. 2 being connecteddirectly to shaft I2 and throttle lever link i0, thereby doing away withthe releasable connection between links and 33 of Fig. 1 or links 30 and33- of Fig. 2. In the Fig. 3 arrangement, there is substituted for thesolenoid actuated clutch of Fig. l or Fig. 2' a friction clutch li whichis biased towardclosed position by a spring 150. 'Clutch Hi is heldclosed with suflicient friction so that when motor l3 corresponding tomotor l3 of Fig. 1 or' motor I3 of Fig. 2, is operated, it can effectadjustmentof the throttle valve, at the same time effecting adjustmentof manual lever 38. At any time, the operator can adjust the throttlemanually by means of lever 38*, the adjustment taking place inopposition to the friction of clutch l8. In I other words, clutch Hi iscapable of being readily slipped by means of the hand lever. Otherwise,the arrangement shown in Fig. 3 may be the same "as that shown in eitherFig. 1 or Fig. 2 and the same reference characters with the exponent badded have been applied to corresponding parts. Only sumcient of themechanismis shown in Fig. 3 to illustrate the modified parts. Theapplication of the Fig. 3 modification to said lever means from thevalve and connecting said automatic means thereto,and means for settingthe automatic means for the desired intake pressure.

3. In combination, an engine, regulating means controlling the output ofthe engine, an electric motor for positioning said regulating means,manual means for positioning said regulating means, circuit closingmeans responsive to an operating condition of the engine, and circuitsconnecting said circuit closing means to said motor, said circuitsincluding a motor circuit and means for closing said motor circuit forsuccessive spaced intervals of time to impart to said regulating meanssuccessive adjustments.

4. In combination, an engine, regulating means controlling the output ofthe engine, an electric ated by the motor after a predetermined numberof successive operations of the relay circuit for effecting continuousoperation of the relay circuit.

5. The combination with an internal combustion engine having regulatingmeans, of auto-v matic means responsive to an operating condition ofsaid engine for positioning the regulating means comprising means forinitially imparting either the Fig. 1 system or the Fig. 2 system willbe obvious from the description already given.

By my invention, I provide an automatic throttle control, the use ofwhich is optional with the operator and which is capable ofmaintaining'a desired intake manifold pressure with a high degree ofaccuracy. At the same time, the apparatus is simple instructure andreliable in operation. l I

In accordance with the provisions of the patent statutes, I havedescribed the principle of operation of my invention, together with theapparatus which I now consider to represent the best embodiment thereof,but I desire to have it understood that the apparatus shown is onlyillustrative and that the invention may be carried out by other means.

to said regulating means a plurality of successive small adjustmentswhich, if insuil'icient, are followed by a greater adjustment.

6. The combination with an internal combustion engine having an intakethrottle valve, of automatic means responsive to engine intake pressurefor positioning said valve comprising means which on a departure ofengine intake pressure from a desired value effects initially aplurality of successive small adjustments of said I valve followed by agreater adjustment if the initial adjustments are insufficient torestore the intake pressure to the desired value.

7. Thecombination with an engine and regulating means for controllingthe output of the engine, of automatic means responsive to an operatingcondition of the engine which upon de- "parture of said operatingcondition from a desired value first imparts to said regulating means aplurality of small successive adjustments which if insufficient torestore said operating conditions to the desired value is followed bycontinuous adjustment until such desired value is restored.

8. The combination with an engine and regudevice to said motor to impartto said motor a plurality of small successive actuations followed bycontinuous actuation.

9. The combination with an internal combustion engine having an intakethrottle valve, of

j a shaft connected to the valve for moving it, a

reversing electric motor for turning the shaft, circuits for operatingthe motor in each direction, means responsive to engine intake pressurefor effecting successive closings of said motor circuits of shortdurations, and means actuated by turning movements of the shaft foreffecting closings of said motor circuits of longer duration.

10. The combination with an internal combuse tion engine having anintake throttle valve, of a shaft connected to the valve for moving it,a reversing electric motor for turning the shaft, motor circuits, apressure responsive device connected to the engine intake, a circuitcloser actuated by the pressure responsive device, a pair of relays,circuits connecting the relay windings to the circuit closer, each relayhaving a contact in a motor circuit and a contact for short-circuitingits winding whereby the relays may efiect successive closings of themotor circuits.

11. In combination, an engine, regulating means for controlling theoutput of the engine, a shaft for positioning said regulating means, areversing electric motor for moving said shaft, circuits for operatingthe motor in each direction, means responsive to an operating conditionof the engine for effecting successive closings of said motor circuit ofshort durations, and means actuated by turning movements of the shaftfor eifecting closings of said motor circuits of longer durations.

12. The combination with an internal combustion'engine having an intakethrottle valve, of a shaft connected to the valve for moving it, areversing electric motor for turning the shaft, motor circuits, apressure responsive device connected to the engine intake, a circuitcloser actuated by the pressure responsive device, a pair of relays,circuits connecting the relay windings to the circuit closer, each relayhaving a contact in a motor circuit and a contact for short-circuitingits winding whereby the relays may effect successive closings of themotor circuits, and means effective after said shaft has moved apredetermined amount for rendering ineffective the contacts forshort-circuiting therelay windings.

13. In combination, an engine, regulating means for controlling theoutput of the engine, a shaft for positioning said regulating means, areversing electric motor for moving said shaft, circuits for operatingthe motor in each direction, a control member moved in response tochanges in an operating condition of the engine, a circuit closeractuated by said control member, a pair of relays, circuits connectingthe relay windings to said circuit closer, each relay having a contactin a motor circuit and a contact for short-circuiting its windingwhereby the relays may effect successive closings of the motor circuits.

14. In combination, an engine, regulating means for controlling theoutput of the engine, a shaft for positioning said regulating means, areversing electric motor for moving said shaft, circuits for operatingthe motor in each direction, a control member moved in response tochanges in an operating condition of the engine, a

circuit closer actuated by said control,member, a pair of relays,circuits connecting the relay windings to said circuit closer, eachrelay having a contact in a motor circuit and a. contact forshort-circuiting its winding whereby the relays may. effect successiveclosings of the motor cirsuits, and meansefiective after said shaft hasmoved a predetermined amount for rendering ineffective the contacts forshort-circuiting the relay windings.

15. In combination, an internal combustion engine, means for controllingthe fuel supply thereto, a hand lever for positioning said means,automatic means responsive to changes in an operating condition of theengine for positioning said means, and means connecting automatic meansto said hand lever for adjusting the setting of said automatic meanswhereby when said hand lever is moved to position said first-namedmeans, it simultaneously adjusts the setting of 17. An internalcombustion engine having a fuel regulating means, an automatic controlactuated by an operating condition of said engine,

adjustable means for varying the setting of said automatic control, asingle hand lever, and-means connecting the hand lever to both saidadjustable means and the fuel regulating means whereby by means of thehand control the fuel regulating means and the adjustable means may besimul-.

taneously positioned.

18. An internal combustion engine having a throttle valve for regulatingthe fuel supply thereto, automatic means responsive to intake manifoldpressure for positioning said throttle valve, adjustable means forsetting said automatic means for a desired intake manifold pressure, asingle hand lever, and means connecting it to said throttle valve and tosaid adjustable means for simultaneously positioning said throttle valveand setting means.

19. An internal combustion engine having a.

throttle valve for regulating the fuel supply thereto, automatic meansresponsive to intake manifold pressure for positioning said throttle Ivalve, adjustable means for setting said automatic means for a desiredintake manifold pressure, a single hand lever, means connecting it tosaid throttle valve and to said adjustable means for simultaneouslypositioning said throttle valve and setting means, and means wherebyafter being set, said automatic means regulates said throttle valveindependently of said hand lever.

20. An internal combustion engine having a throttle valve for regulatingthe fuel supply thereto, a motor for positioning the throttle valve,a'pressure responsive device, means for setting it for a desiredpressure, means connecting the pressure responsive device to said motorto effect adjustment of said throttle valve in response to changes inthe pressure applied to said pressure responsive device, a hand lever,and means connecting it to said throttle valve and to said setting meansfor positioning them simultaneously.

21. An internal combustion engine having a throttle valve for regulatingthe fuel supply thereto, a motor for positioning the throttle valve,

, a pressure responsive device, means for setting it tor a. desiredpressure, means connecting the pressure responsive device to said motorto effect in response to changes in the pressure applied theretoinitially a slow adjustment of said throttle valve which, it insumcient,is followed by a.

more rapid adjustment of said throttle valve, a

hand lever, and means connecting it to said throttle valve and to saidsetting means for positioning them simultaneously.

FRANCIS W. 'I'RUESDELL.

D l S C L A l M E R 2,358,363.Franois W. Truesdell, Marblehead, Mass.CONTROL FOB INTERNAL- COMBUSTION ENGINES OR THE LIKE. Patent datgd Sept.19, 1944. Disclaimer filed Mar. 18, 1947, by the assignee, GemralElectric Company. Hereby enters this disclaimer to claims 15, 17, 18,19, a d 20 of said patent.

[Oflcial Gazette April 15, 1947.]

D] s c; L A l M E R 2,358,363.--Francis W. Truesdell, Marblehead, Mass.CONTROL FOB INTERNAL- OR THE LIKE. Patent datgd Sept. 19, 1944. Dis-COMBUSTION ENGINES claimer filed Mar. 18, 1947, by the magma, GeneralElectric Company.

Hereby enters this disclaimer to claims 15, 17, 18, 19, and 20 of saidpatent.

[Oficial Gazette April 15, 1947 .1

